Referring to FIG. 1, propellant fuel tanks have long been used. Fuel tanks are comprised of a fuel tank top dome, a fuel tank body, and fuel tank bottom dome. The body is a cylindrical body. Each of the domes typically includes a semispherical top and short cylindrical section. The two cylindrical sections are respectively mated to opposing ends of the cylindrical body. As such, the interior of the fuel tank defines an oval cavity in which fuel is disposed.
Such a fuel tank suffers from the problem of wicking remaining residual amounts of fuel left in the tank after much of the fuel has been expended. As such, wicks have been disposed inside the tank to provide surface tension forces. Traditionally, the wicks are designed for each specific mission scenario and tank size. As a result, propellant management devices (PMDs) can be found in numerous sizes and configurations. The wicks for one approach assume the internal oval shape of the tank to provide gas free propellant delivery. Two oval shaped wicks are used. The wicks may be plated wicks. Each oval shape wick has an oval perimeter and a centered oval aperture. Two oval wicks are coupled together at 90° forming four half-oval portions. The two oval wicks are coupled and function as an integrated wick. The two oval wicks are known as insert vanes. The exterior edges of each of the four half-oval portions abut internal sides of the body and domes along four abut at times the tank interior along four respective contacting lines that are 90° apart. Each of the four respective contacting lines extends from the center of the top dome to the center of the bottom dome. Each contacting line touches the sides of the tanks to wick fuel.
The wick is considered a propellant management device. The wick usually is internally attached at both ends of the tank while the four half-oval portions are free to move within the tank. The wick is originally designed with a length to match a stretched tank when the tank is filled with fuel or pressurized, and when the half-oval portions touch the interior of the tank along the contacting lines. However, when the tank is empty, the tank shrinks a small amount causing the half-oval portions to bend and sag within the tank. Any motion of the tank when the tank is not fully pressurized will cause the half-oval portion to wiggle around within the tank when the contacting lines are no longer maintained. Transportation, handling, and general movement of a propellant tank can cause the wick to move within the tank. The result of the wick motions is particulates generated between the edges of the wick and the tank interior surface. The amount of the particulates can be quite large, thus potentially clogging the tank outlet.
To avoid failures, particulate filters may be deployed in the plumbing associated with the tank outlet. The particulates could also plug up thrusters in rocket engines. Particulate clogging valves during fuel dispensing as well as other plumbing associated with dispensing the fuel from or into the tank. To avoid the effects of accumulated particulates, the tanks are typically flushed and cleaned prior to reuse. Particulate contamination may lead to propulsion system failures, and the need for excessive cleaning due to internal tank particulate contamination. These and other disadvantages are solved or reduced using the invention.